FIG. 11 shows a conventional distribution system at a building. In FIG. 11, 1 denotes a building. 2 denotes a receiver switching apparatus installed in an electric room on the basement of the building 1. 3 denotes a circuit breaker. 4 denotes a high-tension bus. 5 denotes circuit breakers. 6 denotes transformers. 7 denotes molded-case circuit breakers associated with loads. 8 denotes cables to be connected to the loads.
The receiver switching apparatus 2 places received power on the high-tension bus via the circuit breakers 3. Branch circuit breakers associated with loads in the building 1 are connected over the high-tension bus 4. Power is fed to the loads via the transformers 6 and molded-case circuit breakers 7. This equipment are usually installed in a main electric room in the basement. In a large-scale building, the equipment is installed in a sub-electric room, which receives power from the main electric room, on each floor. From the electric rooms, cables are laid radially toward loads.
A prior art system relating to loop distribution has been disclosed in Japanese Patent Laid-Open No. 61-8645, which, however, poses a problem concerning the safety within a cable shaft. Besides, when an attempt is made to modify the rating of a branch transformer, a power cut becomes necessary. Thus, the handling efficiency is poor.
A conventional distributor has the aforesaid configuration that cables are laid radially from an electric room to loads. A lot of cables are therefore required, many man-hours are needed for cable connection, and eventually the construction costs become high. Furthermore, it takes a lot of time to complete the construction.
A conventional loop distribution facility has problems concerning safety and handling efficiency.
The present invention attempts to solve the above problems. An object of the present invention is to provide a distributor that can easily be put into operation with a simple configuration. Another object of the present invention is to provide high-safety distribution equipment for a distributor. Yet another object of the present invention is to provide a distributor permitting uninterrupted power feed with high reliability.